Field of the Invention
The present invention relates to a technique for controlling image display during electronic zoom.
Description of the Related Art
Conventionally, a technique has been proposed for solving the issue of display delay in which the timing of display is delayed relative to the timing of image capturing when a fast moving object or the like is displayed in real time, or when a moving image is shot (see Japanese Patent Laid-Open No. 2012-222643 and Japanese Patent Laid-Open No. 2003-323333).
In the above Japanese Patent Laid-Open No. 2012-222643, mitigation of display delay is realized by adjusting the timing of display, but in the case of shooting an object that temporally changes size, position, and the like, such as a fast moving object, if the framerate during display and recording changes, then there is the possibility of motion smoothness being inhibited and the imaged object appearing in an unnatural way.
Also, the technique in the above Japanese Patent Laid-Open No. 2003-323333 controls access to the memory by applying a delay amount such that the reading out of data does not overtake the writing of data with respect to the same memory, but there is the possibility that the timing of the readout will be delayed during electronic zoom. In other words, in the case in which a portion of an image is enlarged due to electronic zoom and is displayed, a portion of the image area written to the memory is cut out, and therefore if the writing and reading out of data is performed with respect to the same memory, there is a possibility that the timing of the readout will be delayed more than it is when electronic zoom is not performed. If this delay exceeds the delay amount set in the above Japanese Patent Laid-Open No. 2003-323333, there are cases in which the display delay amount becomes unstable, and the display delay increases if a delay amount is provided that exceeds that which is necessary to prevent the delay amount for display from becoming unstable.